Endoscopic Stone-Extraction Device

ABSTRACT

An endoscopic stone-extraction device is provided comprising a support filament comprising an end portion having a plurality of stacked loops, a sheath comprising a lumen, wherein the support filament is disposed in the lumen such that the sheath is slideable with respect to the support filament, and a handle comprising an actuator. Movement of the actuator in a first direction retracts the sheath and causes the plurality of stacked loops to expand outside the lumen in an arc-like shape. Movement of the actuator in a second direction advances the sheath and causes the plurality of stacked loops to at least partially collapse inside the lumen. Other embodiments are provides, and any of these embodiments can be used alone or in combination.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.61/833,760, filed Jun. 11, 2013, which is hereby incorporated byreference.

BACKGROUND

Basket-type devices have been used for extracting stones such asureteral stones, calaceal stones and other calculus and the like fromthe renal or biliary systems. Various types of stone extraction basketshave been used in the past to extract stones and stone fragments (orother debris) from various biological systems. A typical stoneextraction basket includes a wire basket carried by one end of a wirethat is received within the lumen of a sheath. The end of the wireopposite the basket is secured to a handle that is used to slide thesheath over the wire, thereby moving the basket into and out of thelumen of the sheath. When the basket is out of the sheath, it expands toreceive a stone. The sheath is then moved toward the basket to reducethe size of the basket openings, and the basket and the enclosed stoneare removed from the body. Ultrasonic, laser, and electro-hydraulictechniques have been used to fragment stones in situ. Typically, thestone fragments are left in the body to be excreted or can attempted tobe removed with a stone extraction basket or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an endoscopic stone extraction device ofan embodiment.

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1.

FIGS. 3, 4 and 5 are detailed views of a thumb wheel included in theembodiment of FIGS. 1 and 2.

FIG. 6 is an exploded perspective view of a portion of the handle andthe end portion of the wire of the embodiment of FIGS. 1 and 2.

FIG. 6 a is an exploded perspective view of the elements 73, 74 of FIG.6 from another viewing angle.

FIG. 7 is a cross-sectional view corresponding to that of FIG. 2 ofanother embodiment.

FIG. 8 is a fragmentary side view of selected elements of the embodimentof FIG. 7.

FIG. 9 is a perspective view of an endoscopic stone-extraction device ofan embodiment.

FIG. 10 is a side view of the endoscopic stone-extraction device of FIG.9.

FIG. 11 is a side view of the endoscopic stone-extraction device of FIG.9 with the plurality of loops collapsed inside the lumen.

FIG. 12 is a side view of the endoscopic stone-extraction device of FIG.9 with the plurality of loops expanding outside the lumen.

FIG. 13 is a side view of the endoscopic stone-extraction device of FIG.9 with the plurality of loops grabbing a stone.

FIG. 14 is a side view of the endoscopic stone-extraction device of FIG.9 with the plurality of loops collecting stone fragments.

FIG. 15 is a perspective view of an endoscopic stone-extraction deviceof an embodiment where at least some of the plurality of loops are ofdifferent sizes and at least some of the different-sized loops arearranged in decreasing-size order to form a hood-like structure.

FIG. 16 is a side view of the endoscopic stone-extraction device of FIG.15 with the plurality of loops collecting stone fragments.

FIG. 17 is a handle of an endoscopic stone-extraction device of anembodiment.

FIG. 18 is a handle of an endoscopic stone-extraction device of anembodiment, wherein the handle has a laser fiber entry port.

FIG. 19A is an illustration of a cross-section of a sheath of anembodiment where a laser fiber is internal to a stone-extractionfilament.

FIG. 19B is an illustration of a cross-section of a sheath of anembodiment where a laser fiber is external to a stone-extractionfilament.

FIG. 20 is an illustration of a two-port endoscope that can be used withan endoscopic stone-extraction device of an embodiment.

FIG. 21 is an illustration of a Y-adapter that can be used with thetwo-port endoscope of FIG. 20.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS Introduction

In a stone-removal procedure, an endoscope (e.g., a ureteroscope) isinserted into the body, with the distal end of the scope near the stoneto be extracted. As shown in FIG. 20, an endoscope 200 typically has twoports 210, 220. One of the ports 210 is typically used as an irrigationport (for saline to be introduced into the extraction site), and thesecond port 220 is used for various instruments. In some situations, thesecond port 220 is initially used for the sheath that holds a stoneextraction basket (however, other situations are possible, as will bediscussed below).

The procedure begins with inserting the endoscope into the body (e.g.,inserting the ureteroscope into the ureter) and identifying and locatingthe stone. Once the stone is identified, a decision is made whether thestone can be extracted out intact or whether the stone needs to befragmented because it is too large to be extracted out. There areseveral technologies that are available for fragmentation, and a popularand effective technology is a laser. One of the problems faced duringfragmentation is retropulsion, whereby the stone migrates up the uretertowards the kidney. Retropulsion makes the procedure more difficult andis associated with more complications.

To prevent migration of the stone, a mechanical device can be used as abackstop to the stone. When a mechanical backstop/trapping device isused, the scope is inserted, the stone is identified, and the mechanicalbackstop device is inserted through one of the ports of the scope (theother port is used as an irrigation channel). The mechanical backstopdevice is then placed beyond the stone and deployed. Since a two-portscope does not have any other access point for the laser fiber, themechanical backstop is left in the body, while the uretroscope isremoved from the body and then reinserted. The stone is identifiedagain, and the laser fiber is then inserted into the open port tofragment the stone. The fragmented stone can be left inside the ureterto be passed out or can be dragged into the bladder and then extractedout either by irrigation or by using a stone basket (the mechanicalbackstop device usually is not very effective in removing stonefragments, which is why the separate stone basket is used).

Instead of using a mechanical backstop device, a gel can be insertedinto the body just beyond the stone, and the patient's body temperatureheats the gel to form a jelly that acts as a backstop to the stone.After the stone fragments have been removed, the physician introducescold saline into the patient, which dissolves the jelly so it can drainout of the ureter. As another alternative to using a mechanical backstopdevice, a standard stone basket can be used to engage the stone. Oncethe stone is engaged, the basket filament and sheath are cut at thehandle and left inside the body. The ureteroscope is then removed, andthe procedure is carried out as mentioned above. However, some stonebaskets, such as a four-wire basket, may not serve as an effectivebackstop since stone fragments can escape from the sides of the basket.

There are several difficulties associated with the current procedure.First, it is a multistep process, requirement the scope to be removedand re-inserted into the patient multiple times. Second, when amechanical backstop device is used, it may not stay in place when thescope is removed and reinserted into the body (e.g., the backstop devicecan move up or down the ureter and sometimes into the kidney or come outin front of the stone instead of staying behind the stone). Third, stonefragments can escape around the backstop device (or a stone basket whena separate backstop device is not used) because these devices do notcompletely occlude the lumen.

The following endoscopic stone-extraction devices can function both as atrapping/backstop device and a stone extraction device, which eliminatesat least one of the steps in the multi-step process described above. Inaddition to being more effective and useful, these devices can be easierto manufacture than traditional stone baskets.

Exemplary Endoscopic Stone-Extraction Devices

FIGS. 9-16 illustrate endoscopic stone-extraction devices of anembodiment. As shown in these figures, the endoscopic stone-extractiondevice 900 has a support filament 910 comprising an end portion having aplurality of loops 920 and a sheath 930 comprising a lumen 940, whereinthe support filament 910 is disposed in the lumen 940 such that thesheath 930 is slideable with respect to the support filament 910. (A“loop” does not necessarily mean a completely closed shape.) A handle1700 (see FIG. 17) comprises an actuator 1710. (Any type of handle withan actuator can be used, and other example of handles are providedbelow. Details of any particular handle design (discussed herein orotherwise) should not be read into the claims unless explicitly recitedtherein). When in the sheath 930, the plurality of loops 920 are stacked(e.g., in generally parallel planes) (see FIG. 11), and movement of theactuator 1710 in a first direction retracts the sheath 930 and causesthe plurality of loops 920 to expand outside the lumen 940 from the axisof the sheath in an arc-like shape. (When expanded in the arc-likeshape, although the loops are no longer generally parallel to eachother, they may still be considered “stacked.”) In one embodiment, thereare no elements extending between or across the plurality of loops 920when the plurality of loops 920 expand outside the lumen 940 (see FIGS.9, 10, 12, and 13). That is, the plurality of loops 920 can compriseonly a set of longitudinal filaments radiating from the end portion ofthe support filament 910 and no lateral filaments. However, in otherembodiments, there can be elements between and/or across the loops. Whendeployed, the plurality of loops 920 can serve as a mechanical backstopto the stone 1000 and can later be used to collect and remove thestones. Accordingly, unlike the prior situation discussed above wheretwo devices (a backstop device and a basket) were used to provide thebackstop and collecting functions, this single device serves bothpurposes.

Movement of the actuator 1710 in a second direction advances the sheath930 and causes the plurality of loops 920 to at least partially collapseinside the lumen 940 (see FIG. 11). Retracting the loops 920 can behelpful in extracting the fragments 1010 after the stone 1000 has beenshattered. As shown in FIG. 11, when the plurality of loops 920 arecollapsed inside the lumen 940, the plurality of loops 920 are againstacked. While the loops 920 are stacked on top of one another in thisembodiment, in another embodiment (shown in FIGS. 15 and 16), the loopsare stacked in a nested fashion. Accordingly, the term “stacked” doesnot necessarily imply directly on top of one another. Also, the loopscan be nested inside of one another (in the same plane or in parallelplanes) when in the sheath and then become stacked when expanded outsideof the sheath. As shown in FIGS. 10, 12, and 13, when the plurality ofloops 920 expand outside the lumen 940, the plurality of loops 920 fanout from the axis of the sheath in an arc less than 180 degrees,although other arrangements are possible.

There are many variations that can be used. For example, while theplurality of loops 920 in the embodiment in FIGS. 9-14 are of generallythe same size, FIGS. 15 and 16 show an embodiment in which at least someof the plurality of loops 1500 are of different sizes, and wherein atleast some of the different-sized loops 1500 are arranged indecreasing-size order to form a hood-like structure. As with theabove-described embodiment, these loops are stacked when in the sheath,although in a nested fashion (in the same plane or in parallel planes)and not directly on top of one another). As also with theabove-described embodiment, movement of the handle actuator in a firstdirection retracts the sheath and causes the plurality of loops toexpand outside the lumen from the axis of the sheath in an arc-likeshape. While the drawings show that there are no elements extendingbetween or across the plurality of loops when the plurality of loopsexpand outside the lumen, in other embodiment, such elements can bepresent.

Regarding construction, the plurality of loops can be formed from aplurality of individual filaments, all of which are joined (e.g.,welded, soldered, swaged or otherwise held in place) to the supportfilament, or the plurality of loops are formed from a single filament.That single filament can be the support filament or can be a filamentthat is separate from but joined to the support filament. In oneembodiment, each of the loops is a closed shape. Also, in oneembodiment, the loops are joined only at one end (e.g., in contrast to afour-wire basket where the wires are joined on two ends). Further, theplurality of loops can be made from a shape memory metal, such asnitinol, although other materials can be used. In one embodiment, theloop can be made from preferably small, flexible, kink-resistant wiresthat are capable of collapsing together to fit within the lumen. Also,the loops can be sized in any suitable fashion. For example, in oneembodiment, the opening of the loop can be sized to admit a stone thatis at least two millimeters in diameter (or less) or as large as 5 mm(or more) in diameter. Of course, other sizes and ranges can be used.

Exemplary Handles

As noted above, any type of handle can be used with the stone-extractiondevices of these embodiments. For example, the handle 1700 can simply bya device with an actuator 1710 to deploy the plurality of loops (as inFIG. 17). In another embodiment (see FIG. 18), the handle 1800 not onlyhas an actuator 1810, but also has a port 1820 for a laser fiber 1830.(The omniFORCE™ Laser Stone Cage by Omnitech Systems is an example ofsuch a handle.) As shown in FIGS. 19A and 19B, the laser fiber 130 caneither be internal to (FIG. 19A) or external to (FIG. 19B) the filament1900, 1910 within the sheath 1840. The advantage of using this type ofhandle 1800 is that a two-port scope does not need to be removed andreinserted into the body in order to provide a free port for the laserfiber, as the laser fiber is already provided in the sheath 1840.Another way of obtaining this advantage of not removing the scope is byusing a Y-adaptor 2100 (see FIG. 21) that would fit on one of the ports220 of the scope 200, allowing both the stone-extraction sheath and thelaser fiber to used the same port 220 on the scope 200. (The Y-adaptorused with the Escape® Basket from Boston Scientific is an exemplaryadaptor.) In this alternative, it is preferred that the sheath and thelaser fiber be sized so that they can both fit together inside the port220.

As mentioned above, other handle designs can be used. The followingparagraphs and drawings describe yet another handle design. Again, thisand the other handle designs described herein are merely examples andshould not be read into the claims.

Returning to the drawings, FIG. 1 shows an endoscopic stone extractiondevice 10 of an embodiment. The device 10 includes a handle 12 that inturn includes a grip 14 and a slide 16. As explained in greater detailbelow, the slide 16 is mounted to slide longitudinally along the lengthof the grip 14.

A tubular sheath 18 is secured to the slide 16. The sheath 18 defines alumen 19, and the sheath 18 can be formed of any suitable flexiblematerial. A strain relief collar 20 is provided at the point where thesheath 18 is secured to the slide 16 to reduce the incidence of kinking.

The device also includes a filament 22 having a first end 24 (FIG. 2)and a second end 26 (FIG. 1). The first end 24 is rotatably secured tothe grip 14 (FIG. 2), and the second end 26 supports a stone extractionbasket (this basket is of a different shape than the stone-extractiondevice discussed above, as this handle can be used with a variety ofbaskets). The filament 22 can be formed of any suitable material, and istypically formed of a flexible metallic wire. Preferably, the first end24 is thicker and stiffer than the second end 26 to facilitate insertionand manipulation of the basket 28.

The following sections will first describe the handle 12 in greaterdetail.

As best shown in FIG. 2, the handle 12 includes a tube 30 that defines alongitudinally extending slot 32. The tube 30 forms a bore 34 andterminates at one end in external threads 36. Protruding elements 38extend away from the perimeter of the tube 30 to facilitate the graspingof the tube 30 by a physician during use. For purposes of discussion,the portion of the tube 30 adjacent the external threads 36 will bereferred to as the rear portion 42, and the opposite end of the tube 30will be referred as the front portion 40. The tube 30 may for example beformed of any suitable, moldable thermoplastic material, though thewidest variety of materials can be adapted for use.

Continuing with FIG. 2, the slide 16 includes a guide cylinder 50 sizedto slide along the bore 34 of the tube 30. This guide cylinder 50defines a central opening 52 sized to pass the filament 22 with littleor no friction therebetween. The slide 16 also includes an arm 54 thatextends from the guide cylinder 50 through the slot 32 to a plate 56.The arm 54 holds the plate 56 in alignment with the centerline of thetube 30. The slide 16 includes a gripping portion 58 that can be pushedor pulled by a physician during use to move the slide 16 along thelongitudinal axis of the tube 30. As before, a wide range of materialscan be used for the slide 16, including any suitable thermoplasticmaterial.

As shown in FIGS. 1-5, a disk 60 is provided. This disk 60 is positionedadjacent the front portion 40 of the tube 30. The disk 60 is clampedonto the filament 22, and the disk 60 is rotatable with respect to boththe tube 30 and the slide 16. As shown in FIGS. 3-5, the disk 60includes half-disks 66, 68 that snap together in a releasable manner.The half-disks 66, 68 carry respective elastomeric gripping portions 69designed to grip the filament 22 therebetween when the half-disks 66, 67are snapped together.

As best shown in FIGS. 1, 2, 6 and 6 a, the handle 12 carries a threadedcap 70 that defines a set of internal threads sized to mate with theexternal threads 36. The cap 70 includes a socket 71 that bears on achuck 72. When the cap 70 is tightened in place, the chuck 72 is heldbetween the socket 71 and an internal socket 31 formed by the tube 30.The chuck 72 is free to rotate but not to translate with respect to thetube 30.

The chuck 72 includes two parts 73, each having a central groove 77sized to clamp against the filament 22. The groove 77 may be lined withan elastometric layer to ensure good frictional contact between thechuck 72 and the filament 22. Each part 73 defines external threads, andthe parts 73 are clamped against the filament by a cap nut 74 such thatthe chuck 72 rotates and translates in unison with the filament 22. Thechuck 72 forms a convex surface 75 that engages the socket 31, and aconvex surface 76 that engages the socket 71. The surfaces 75, 76 areshaped to allow low-friction rotation of the chuck 72 and the filament22 relative to the tube 30. Thus, the chuck 72 and associated elementscarried by the tube 30 form a rotational joint. Other types ofrotational joints may be used, including ball-and-socket joints. Forexample, a ball-and-socket joint may be included in the filament 22 nearthe first end 24, and the first end 24 may be fixed to the tube 30.Also, the filament may have an enlarged end that forms part of therotational joint, and the enlarged end may be sized to fit through thelumen of the sheath 18. Alternatively, the enlarged end may be too largeto fit through the lumen of the sheath, and may be removable from thebody of the filament 22, e.g. by disassembling the enlarged end from thefilament 22.

In use, the device 10 is assembled as shown in FIGS. 1 and 2. Initially,the slide 16 is advanced (i.e. moved to the right in the view of FIG. 2)to move the sheath 18 over the basket 28. This reduces thecross-sectional dimensions of the basket 28 and facilitates insertion ofthe basket 28 into a region of the body adjacent to the stone to beremoved. The slide 16 is then moved to the left in the view of FIG. 2 toexpose the basket 28, which resiliently assumes an enlarged operationalshape.

It should be apparent from the foregoing discussion that rotation of thedisk 60 and the filament 22 occurs without rotation of the sheath 18,the slide 16 or the handle 12. This arrangement facilitates rotation ofthe filament 22 and the basket 28 inside the lumen of the body cavity inwhich it is inserted, since friction between the sheath 18 and theendoscopic device and between the sheath 18 and adjacent tissue do notimpede rotation of the filament 22 and the basket 28. Rotation of thefilament 22 is guided by the rotational joint that includes the chuck72. Once a stone has been captured within the basket, the slide 16 isthen moved to the right in the view of FIG. 2 to move the sheath over atleast a portion of the basket, thereby securely capturing the stone inthe basket for removal.

On occasion, it may be necessary to remove the handle 12, the slide 16and the sheath 18 while leaving the filament 22 and the basket 28 inplace. This can readily be accomplished by unscrewing the cap 70 fromthe handle 12, removing the cap nut 74 from the parts 73, and thenremoving the parts 73, handle 12, slide 16 and sheath 18 from thefilament 22.

The disk 60 is an example of a manipulator used to rotate the filament22 relative to the handle 12. This manipulator can take other forms,including the form shown in FIGS. 7 and 8. The embodiment of FIGS. 7 and8 is similar to that of FIGS. 1 and 2, except that the disk 60 has beenreplaced by a lever 80. This lever 80 defines a free end 82 and hingedend 84, and the free end 82 is positioned closer to the first end 24 ofthe filament 22 than is the hinged end 84. During normal use, the lever80 is positioned as shown in FIG. 7 in an extended position. In thisposition the user can apply torques to the lever 80 and therefore to thefilament 22 to rotate the filament 22 as described above. The hinged end84 is connected to the filament 22 at a hinged joint (e.g. a livinghinge or a multiple-part hinge) and the lever 80 can be moved to theretracted position shown in dotted lines in FIG. 8. In this retractedposition, the lever 80 can be moved through the lumen of the sheath 18,thereby allowing the handle, slide and sheath to be removed from thefilament 22 as described above.

CONCLUSION

It should be apparent from the foregoing detailed description thatimproved endoscopic stone extraction devices have been described thatare well suited to the collection of a wide variety of stones, includingstone fragments. The baskets described above are well suited for theremoval of many types of debris, including for example, stones, stonefragments, and cholesterol plaque fragments. The devices described abovecan be used with the widest variety of endoscopes, includingureteroscopes, nephroscopes and other endoscopic devices, and they canbe used within the lumens of many body tissues, including for example,ureters, bile ducts, and blood vessels.

As used herein, the term “stone” is intended broadly to encompass a widevariety of biological stones, calculus and the like, including fragmentsof stones, calculus and the like formed by any of the techniquesdescribed above or other techniques developed in the future. Urinarytract stones and biliary tract stones are two examples.

The term “end portion” is intended broadly to encompass the end ofstructure such as a filament along with an adjacent portion of thestructure.

The term “surface” is intended broadly to encompass perforated surfaces.

The term “filament” is intended broadly to encompass wires and otherelongated structures formed of any of a wide range of materials,including metals, plastics, and other polymers.

Also, any of the embodiments in the following documents, which arehereby incorporated by reference, can be used in combination with theembodiments discussed herein: U.S. Pat. Nos. 6,743,237; 7,087,062;6,419,679; 6,494,885; and 6,551,327.

The foregoing detailed description has discussed only a few of the manyforms that this invention can take. For this reason, this detaileddescription is intended by way of illustration and not limitation. Itonly the following claims, including all equivalents, that are intendedto define the scope of this invention.

What is claimed is:
 1. An endoscopic stone-extraction device comprising:a support filament comprising an end portion having a plurality ofstacked loops; a sheath comprising a lumen, wherein the support filamentis disposed in the lumen such that the sheath is slideable with respectto the support filament; and a handle comprising an actuator; whereinmovement of the actuator in a first direction retracts the sheath andcauses the plurality of stacked loops to expand outside the lumen in anarc-like shape; and wherein movement of the actuator in a seconddirection advances the sheath and causes the plurality of stacked loopsto at least partially collapse inside the lumen.
 2. The endoscopicstone-extraction device of claim 1, wherein when the plurality ofstacked loops expand outside the lumen, the plurality of stacked loopsfan out in an arc less than 180 degrees.
 3. The endoscopicstone-extraction device of claim 1, wherein the plurality of stackedloops are the same size.
 4. The endoscopic stone-extraction device ofclaim 1, wherein at least some of the plurality of stacked loops are ofdifferent sizes, and wherein at least some of the different-sized loopsare arranged in decreasing-size order to form a hood-like structure. 5.The endoscopic stone-extraction device of claim 1, wherein when theplurality of stacked loops are collapsed inside the lumen, the pluralityof stacked loops are positioned on top of one another.
 6. The endoscopicstone-extraction device of claim 1, wherein there are no elementsextending between or across the plurality of stacked loops when theplurality of stacked loops expand outside the lumen
 7. The endoscopicstone-extraction device of claim 1, wherein the plurality of stackedloops comprises only a set of longitudinal filaments radiating from theend portion of the support filament and no lateral filaments
 8. Theendoscopic stone-extraction device of claim 1, wherein the plurality ofstacked loops are formed from a plurality of individual filaments, allof which are joined to the support filament.
 9. The endoscopicstone-extraction device of claim 1, wherein the plurality of stackedloops are formed from a single filament.
 10. The endoscopicstone-extraction device of claim 9, wherein the single filament is thesupport filament.
 11. The endoscopic stone-extraction device of claim 9,wherein the single filament is separate from but joined to the supportfilament.
 12. The endoscopic stone-extraction device of claim 1, whereinthe plurality of stacked loops are made from a shape memory metal. 13.The endoscopic stone-extraction device of claim 12, wherein the shapememory metal comprises nitinol.
 14. The endoscopic stone-extractiondevice of claim 1, wherein the handle includes a laser fiber port. 15.The endoscopic stone-extraction device of claim 1, wherein the sheath issized to fit along side a laser fiber in a port of an endoscope via aY-adaptor.
 16. The endoscopic stone-extraction device of claim 1,wherein distal ends of the plurality of stacked loops arc outwardly froma longitudinal axis of the lumen.
 17. The endoscopic stone-extractiondevice of claim 1, wherein proximal ends of the plurality of stackedloops meet at a single point.
 18. The endoscopic stone-extraction deviceof claim 1, wherein other than at a single connection point, theplurality of stacked loops are non-intersecting.
 19. The endoscopicstone-extraction device of claim 1, wherein other than a connectionpoint, the plurality of stacked loops are independent from one another.